Premium
High‐frequency internal waves and thick bottom mixed layers observed by gliders in the Gulf Stream
Author(s) -
Todd Robert E.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl072580
Subject(s) - underwater glider , geology , internal wave , bathymetry , continental shelf , buoyancy , glider , plateau (mathematics) , oceanography , internal tide , gulf stream , current meter , turbulence , underwater , meteorology , geography , mathematical analysis , physics , mathematics , quantum mechanics , marine engineering , engineering
Autonomous underwater gliders are conducting high‐resolution surveys within the Gulf Stream along the U.S. East Coast. Glider surveys reveal two mechanisms by which energy is extracted from the Gulf Stream as it flows over the Blake Plateau, a portion of the outer continental shelf between Florida and North Carolina where bottom depths are less than 1000 m. Internal waves with vertical velocities exceeding 0.1 m s −1 and frequencies just below the local buoyancy frequency are routinely found over the Blake Plateau, particularly near the Charleston Bump, a prominent topographic feature. These waves are likely internal lee waves generated by the subinertial Gulf Stream flow over the irregular bathymetry of the outer continental shelf. Bottom mixed layers with O(100) m thickness are also frequently encountered; these thick bottom mixed layers likely form in the lee of topography due to enhanced turbulence generated by O(1) m s −1 near‐bottom flows.